Design And Research Of Multi-angle And Double-band Atmospheric Sounding Spectrometer

Aerosols,water vapor and clouds are three important parameters affecting global climate and environmental change.Through the long-term accumulation of data on the spatial and temporal distribution of these three parameters,human beings could be better guided to adapt and regulate the trend of climate change.Remote sensing techniques(including space-based,air-based and ground-based)are the main means for obtaining long-term observation data.The demand for remote sensing of aerosol,water vapor and cloud parameters are mainly in three terms: acquisition of aerosol profiles,analysis of the interaction between aerosols,water vapor and clouds,and global-scale detection.At present,the main means to achieve global-scale atmospheric parameter detection are space-based observations and ground-based observations.The existing ground-based instruments are mostly sun photometers and radiometers,which are limited by the resolution and unable to achieve the inversion of aerosol profiles on the one hand,while on the other hand,they are limited by the detection mode and unable to achieve simultaneous multi-band detection.In this paper,based on the advantages and disadvantages of existing remote sensing instruments,a ground-based multi-angle dual-band high-resolution simultaneous detection model is proposed,and based on the analysis of the principle and feasibility,an atmospheric sounding spectrometer prototype is built to test the feasibility of this atmospheric remote sensing detection model.The simultaneous detection of aerosol,water vapor and cloud is beneficial to analyze their interactions,the multi-angle mode is beneficial to obtain more independent information amount in atmospheric parameters,and the high spectral resolution is beneficial to obtain the profile information of aerosol and water vapor.In this paper,the theoretical research and experimental validation are carried out around the above requirements in terms of feasibility assessment,analysis of key parameters,optical machine structure design,thermal analysis and simulation,as well as calibration and field testing.The main research contents of this paper are as follows:(1)Study of atmospheric orthoretic model and inversion theory.The basic principle of hyperspectral atmospheric sounding is introduced by radiative transfer equation,the inversion simulation is used to demonstrate the inversion capability of oxygen A-band on aerosol profile,and the influence of different spectral resolution,stray light suppression and signal-to-noise ratio on the inversion accuracy of the instrument is analyzed,and the key technical parameters of the atmospheric sounding spectrometer are clarified.(2)Optical and mechanical structure design and thermal analysis of the multi-angle dual-band atmospheric sounding spectrometer.The optical design of the multi-angle front telescope and the dual-band co-detector spectrometer was firstly carried out based on the usage requirements and working mode,and the stray light suppression problem including spectral overlap was mainly solved in this part.Then the structural design of the atmospheric sounding spectrometer was carried out based on the design parameters of the optical system and the feasibility of mounting,which mainly solved the temperature adaptation problem of the long-span spectrometer.Finally,the finite element analysis and optical simulation of the instrument were carried out to verify the results of the optical mechanical design results.(3)Research on the integration and spectral calibration of the atmospheric sounding spectrometer prototype.Firstly,he installation and adjustment of the transmissive telescope system and the reflective spectrometer system was studied,after the prototype was integrated,spectral resolution and other important indexes were initially tested.Then the spectral calibration of the two bands was studied,for the characteristics of high spectral resolution in the oxygen A band,a scheme of joint calibration of tunable laser and wavelength meter was developed,for the characteristics of wide spectral range in the 820 nm water vapor absorption band,a scheme of joint calibration with mercury lamp,super continuous spectrum laser and monochromator was developed.Finally,the spectral response functions of each spectral channel were analyzed and the central wavelength was fitted to verify the results of the design and mounting of the optical-mechanical system.(4)Research on the radiometric calibration and field test of the prototype of atmospheric sounding spectrometer.Firstly,research on the signal-to-noise ratio and response linearity of the prototype was conducted for radiometric calibration,and the problem of the signal-to-noise ratio not meeting the usage requirements was solved by using the spatial dimensional pixel binning.Secondly,the uncertainties in the calibration process were analyzed,and the relative uncertainties and absolute uncertainties of the prototype calibration were derived.Thirdly,the prototype was tested under different temperature environments,and the stability of the prototype operation and the Finally,the prototype was tested under different temperature environments,and the drift of the spectral position was tested to verify the development theory of the prototype atmospheric sounding spectrometer.